In fifth grade I watched The Voyege Of The Mimi
and I got interested in whales. I heard that
whales walked on land and there food was in the
water so they adapted to the water. I want to
know if there is some more evidence that whales
walked on land.

Question Date: 1999-11-15

Answer 1:

Great question! Whales are so obviously water
creatures, right? We've all seen pictures of
whales washed up on the beach and it's quite clear
that whales aren't well adapted to terrestrial
(land) habitats. So, what evidence is there for
the idea that whales "once walked on
land?"

The answer is actually very simple.
Whales never walked on land! Rather, the ancestor
to whales walked on land. This is an important
difference. You see, whales are mammals. They are
closely related to other animals with hair -
horses, dogs, monkeys, rats and even humans. But,
millions of years ago whales as we know them today
did not exist - they had not yet evolved. Instead,
there was a kind of mammal with four legs that
roamed the earth above water. These animals were
well adapted for living on the land; they could
breath the air, walk on land and capture food just
as other mammals can. These were the ancestors to
whales.

It is thought that over time, these
four-legged creatures began to spend a lot of time
in the water, probably fishing for food. Over
thousands of generations, these land-based
creatures began to change in ways that helped them
live more easily in the water. One of the most
obvious changes was the loss of legs and the
addition of a powerful tail for swimming. As time
progressed, these animals became more fish-like
and less mammal-like. These fish-like mammals are
what we now call Whales. So, again, whales
themselves never walked on land. The ancestors to
whales, a primitive mammal, walked on
land.

Now, how do we know that whales had
ancestors that walked on land? There are many
reasons why we know this is true, but one of the
most compelling lines of evidence is that whales
have a pelvis. Animals that walk on land have a
pelvis which is an important structure to which
legs attach. Except for whales, animals that live
in the water don't have a pelvis. Why? Because
there's no need to have legs for walking if you
live in the water. The reason why whales have a
pelvis is because they are descendent from animals
that walked on land - the ancestors to whales were
terrestrial! Whales don't use their pelvis
anymore.

So, we know whales had ancestors
that walked on the land because they have a pelvis
- a feature common to all walking mammals - which
used only for terrestrial purposes. Now you might
ask yourself, what is the name of this whale-like
ancestor that walked on land? What did it look
like? You may find the answer to this question at
this web
site:

http://library.advanced.org/17963/evolution.html

Answer 2:

by studying the morphology and anatomy of fossil
bones, it is possible to follow a transition from
legs to strong flippers.This change occurred over
a long time period...perhaps 20 to 30 million
years. In fact the most distant relative of the
modern whale may be the Hippo.you can learn more
about this subject in the library. one place to
look id for a book on vertebrate zoology and
paleontology.

Answer 3:

It is pretty impossible to imagine whales walking
on land. In fact scientists don't think they ever
did. What we think is that their distant
ancestors did. The earliest mammals were
terrestrial (land) animals. Since whales are
mammals, we think they must have descended from
land mammals too. (What is a mammal?)

The
earliest known whale-like fossils were found in
Pakistan. (Take a look at a map to find Pakistan.
Why would we find whale-like things here?) The
fossils seem to be about 45-50 million years old.
The discoverers think that these animals lived
part of their lives on land and part of their
lives in water. Can you think of another type of
mammal that lives like this? These early animals
were only about 3 meters long. Other fossilized
bones were found of animals that scientist think
lived about 40 million years ago. They were
shaped a lot more like our modern whales, but
might have still come on shore to give birth. As
you probably know, there are lots of different
kinds of whales now. Most of these species
probably evolved in the last 2-30 million years
ago. Another interesting bit of evidence that
suggests whales descended from land animals is the
fact that they still have a tiny pelvis and thigh
bone (femur). In a 19 m long finback whale, the
pelvis is only 41 cm long and the thigh bone is
only 4 cm long. How tall are you in meters? How
long is your thigh?